Lenses

Im new in the dslr world and i have heard alot of talk about choosing the lense first before the camera. I am going to purchase the a100 because it is a great entry level camera. I was wondering if anyone thinks that the sony lenses can compete with nikon or canon the older competitors. Also if i am looking into architecture at college, and was wondering the lens to purchase for those type of shots. does anyone think that the sony lenses are relatively expensive for what they offer or if any of them are not as great quality?.